Update README.md (#129)

Add deprecation warning + link to new test reporter

Author: davehenton

Diff for: README.md

@@ -2,7 +2,9 @@
 [![Code Climate](https://codeclimate.com/github/codeclimate/php-test-reporter.svg)](https://codeclimate.com/github/codeclimate/php-test-reporter)
 [![Test Coverage](https://codeclimate.com/github/codeclimate/php-test-reporter/badges/coverage.svg)](https://codeclimate.com/github/codeclimate/php-test-reporter/coverage)
 
-# codeclimate-test-reporter
+# codeclimate-test-reporter - [SOON TO BE DEPRECATED]
+
+These configuration instructions refer to a language-specific test reporter that will soon be deprecated in favor of our new unified test reporter client. The [new test reporter](https://docs.codeclimate.com/v1.0/docs/configuring-test-coverage) is faster, distributed as a static binary, has support for parallelized CI builds, and will receive ongoing support by the team here. The existing test reporters for Ruby, Python, PHP, and Javascript are not yet deprecated but they're unofficially in maintenance mode.
 
 Collects test coverage data from your PHP test suite and sends it to
 Code Climate's hosted, automated code review service.